International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Impact Factor (2012): 3.358
Renewable Energy Source Applications in
Multilevel Inverter Based Induction Motor Drive
Using ANN
G. Sathish Goud 1, Venkateswarlu Kalimela2
1
Student, Department of EEE, AITH, JNTUH, Hyderabad, India
2
Assistant Professor, Department of EEE, AITH, JNTUH, Hyderabad, India
Abstract: This paper presents optimized multilevel inverter topology is proposed for a four pole induction motor drive. The open-end
winding scheme, the Induction Motor windings are fed from both sides with two two-level inverters (with half the dc-link voltage when
compared with conventional NPC inverter) to get a three-level inverter topology. With this concept as the number of levels increases, the
inverters have to be cascaded or a conventional multi-level inverters have to be used on both the sides of the Induction Motor winding.
This topology has developed by using the advantage of two identical voltage profile winding coils per phase in a four pole induction
motor drive using Ann. Further the DC source is replaced by a renewable resource such as solar panels, wind power etc. and DC voltage
is obtained. Performance characteristics of three-phase asynchronous motor are analyzed with PV array connected. The method can be
easily extended to a multilevel inverter. The proposed concept is verified by using Matlab/Simulink software and the corresponding
results are presented.
Keywords: Multilevel inverter, Induction motor, Sine triangle PWM, ANN.
1. Introduction
The voltage source inverters produce a voltage or a current
with levels either 0 or ±V dc they are known as two level
inverters. In high power and high voltage applications, these
two level inverters, however, have some limitations in
operating at high frequency mainly due to switching devices
should be used in such a manner as to avoid problems
associated with their series- parallel combinations that are
necessary to obtain capability of handling high voltages and
currents. It may be easier to produce a high power, high
voltage inverter with the multi-level structure because of the
way in which device voltage stresses are controlled in the
structure. Cascaded H-bridge MLIs are mostly preferred for
high power applications as the regulation of the DC bus is
simple. But it requires separate dc sources and also the
complexity of the structure is increases as the level
predominantly increase. The other alternate topology is open
end winding induction motor drive fed with two-level (or
multi-level) inverters. Multilevel inverter technology has
been widely used for the control of medium and high voltage
AC drive applications from the past few decades because of
its improved output voltage quality, better harmonic
performance, less voltage stress on power electronic devices
and etc. Many multilevel inverter configurations are
presented to improve the output voltage harmonic spectrum
and to reduce the circuit complexity and to reduce the
number of switches. Many Pulse Width Modulation (PWM)
techniques are proposed to improve the harmonic spectrum
of the voltage and currents. In this paper a multilevel inverter
topology is proposed for the induction motor drive by using
four conventional two-level inverters only, with the
advantage of two identical voltage profile winding coils of
four pole induction motor. The identical voltage profile
winding coils are disconnected and each part of the winding
is fed with two two-level inverters from both sides. Thereby
Paper ID: 03111405
four two-level inverters are used to generate five voltage
levels on motor phase windings. All two-level inverters are
fed with single DC link with the magnitude VDC/4. The
proposed topology uses sine-triangle PWM to generate the
pulses for the switches of each inverter which will also
minimize the common mode currents circulating in the motor
phase windings because of the common DC link.
2. Mathematical Model of the PV Array
2.1 Simplified Equivalent Circuit:
Figure 1: PV cell equivalent circuit
The complex physics of the PV cell can be represented by
the equivalent electrical circuit. The circuit parameters are as
follows. The current I at the output terminals is equal to the
light-generated current IL, less the diode current Id and the
shunt-leakage current Ish. The series resistance Rs represents
the internal resistance to the current flow, and depends on
the pn junction depth, impurities, and contact resistance. The
shunt resistance Rsh is inversely related to the leakage current
to ground. In an ideal PV cell, Rs = 0 (no series loss), and
Rsh =(no leakage to ground). In a typical high-quality 1 in.2
silicon cell, Rs varies from 0.05 to 0.10  and Rsh from 200
to 300 . The PV conversion efficiency is sensitive to small
variations in Rs, but is insensitive to variations in Rsh. A
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International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Impact Factor (2012): 3.358
small increase in Rs can decrease the PV output
significantly. In the equivalent circuit, the current delivered
to the external load equals the current IL generated by the
illumination, less the diode current Id and the shunt leakage
current Ish. The open-circuit voltage Voc of the cell is
obtained when the load current is zero, i.e., when I = 0, and
is given by the following:
Voc=V+IRsh
The shunt resistance (Rsh) is very large and the series
resistance (Rs) is very small. Therefore, it is common to
neglect these resistances in order to simplify the solar cell
model. The resultant ideal voltage-current characteristic of a
photovoltaic cell is given by the relation below and
illustrated by the figure above.
I=Iph-ID
I=Iph-I0
Where,
Iph = photocurrent,
ID = diode current,
I0 = saturation current,
A = ideality factor,
q = electronic charge 1.6x10-9,
kB = Boltzmann’s gas constant (1.38x10-23),
T = cell temperature,
Rs = series resistance,
Rsh = shunt resistance,
I = cell current,
V = cell voltage
The power output of a solar cell is given by
PPV = VPV * IPV
Where,
IPV = Output current of solar cell (A).
VPV = Solar cell operating voltage (V).
PPV =Output power of solar cell (W).
The power-voltage (P-V) characteristic of a photovoltaic
module operating at a standard irradiance of 1000 W/m2 and
temperature of 25oC is shown below.
excellent speed and torque response. But, they have the
inherent disadvantage of commutator and mechanical
brushes, which undergo wear and tear with the passage of
time. In most cases, AC motors are preferred to DC motors,
in particular, an induction motor due to its low cost, low
maintenance, lower weight, higher efficiency, improved
ruggedness and reliability. All these features make the use of
induction motors a mandatory in many areas of industrial
applications. The advancement in Power electronics and
semiconductor technology has triggered the development of
high power and high speed semiconductor devices in order
to achieve a smooth, continuous and low total harmonics
distortion (THD). Three phase induction motors are
commonly used in many industries and they have three
phase stator and rotor windings. The stator windings are
supplied with balanced three phase ac voltages, which
produce induced voltages in the rotor windings due to
transformer action. It is possible to arrange the distribution
of stator windings so that there is an effect of multiple poles,
producing several cycles of magneto motive force (mmf)
around the air gap. This field establishes a spatially
distributed sinusoidal flux density in the air gap. In this
paper three phase induction motor as a load. The equivalent
circuit for one phase of the rotor is shown in figure. Steady
state Equivalent circuit of an induction motor
Figure 3: Equivalent circuit refer to stator
The rotor current is
Ir = sEr/Rr + jXr
4. Artificial Neural Network
Figure 2: Power-Voltage (PV) Characteristic of a
Photovoltaic Module.
3. Induction Motor
In recent years the control of high-performance induction
motor drives for general industry applications and
production automation has received widespread research
interests. Induction machine modeling has continuously
attracted the attention of researchers not only because such
machines are made and used in largest numbers but also due
to their varied modes of operation both under steady and
dynamic states. Traditionally, DC motors were the work
horses for the Adjustable Speed Drives (ASDs) due to their
Paper ID: 03111405
Once a network has been structured for a particular
application, that network is ready to be trained. To start this
process the initial weights are chosen randomly. Then, the
training, or learning, begins. There are two approaches to
training – ‘SUPERVISED’ and ‘UNSUPERVISED’.
Supervised training involves a mechanism of providing the
network with the desired output either by manually
“grading” the network’s performance or by providing the
desired outputs with the inputs. Unsupervised training is
where the network has to make sense of the inputs without
outside help. The vast bulk of networks utilize supervised
training. Unsupervised training is used to perform some
initial Characterization on inputs.
Training can also be classified on basis of how the training
pairs are presented to the network. The Mat lab
Programming Of ANN Training is as given Below:
net=newff(minmax(P),[7,21,3],
{„tansig‟,‟tansig‟,‟purelin‟},‟trainlm‟);
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1092
International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Impact Factor (2012): 3.358
net.trainParam.show =50;
net.trainParam.lr = .05;
net.trainParam.mc = 0.95;
net.trainParam.lr_inc = 1.9;
net.trainParam.lr_dec = 0.15;
net.trainParam.epochs = 1000;
net.trainParam.goal = 1e-6;
[net,tr]=train(net,P,T);
a=sim(net,P);
gensim(net,-1);
connected to a three phase source feeding dynamic motor
loads is developed using Simulink of MATLAB software.
Simulated results demonstrate that multi level inverter can be
considered as a variable solution for solving such voltage
stresses problems. This thesis work aims at developing a
multilevel inverter for induction machines with voltage
stress and improve the output voltage harmonic spectrum
and to reduce the circuit complexity and to reduce the
number of switches.
The compensator output depends on input and its evolution.
The chosen configuration has seven inputs three each for
reference load voltage and source current respectively, and
one for output of error (PI) controller. The neural network
trained for outputting fundamental reference currents. The
signals thus obtained are compared in a hysteresis band
current controller to give switching signals.
5. Simulation Results and Discussions
This paper deals with the design and implementation of a
multilevel inverter based on three-phase induction motor
(IM) under artificial neural network (ANN) technique in a
MATLAB/Simulink. Circuit diagram as shown in above fig.
This large voltage stress is encountered at the starting of
induction motor However, the voltage stress is now within
limits as the motor is already started and is drawing normal
full rated current, shows the stator current, rotor current, load
voltage, speed, torque with respect to time. The multi level
inverter helps to reduces switching losses.
The waveform can be represented multilevel inverter outputs
the switches operated in different levels. Waveforms are
having switching modules
In This paper, the proposed model of multilevel inverter
Paper ID: 03111405
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International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Impact Factor (2012): 3.358
Multilevel Current
Multilevel Voltage
Three Phase Current
Paper ID: 03111405
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Three Phase voltage
5.1 PV cell input with ANN
The above waveforms can be represents PV cell input powers with MPPT and without MPPT and Dc voltage. When in this
we can use all non conventional energy sources for input of multilevel inverter.
5.2 Induction motor output with ANN
Paper ID: 03111405
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The above waveforms can be represents induction motor stator current, rotor current, load voltage, speed, torque. IM torque
with ANN will be better compared to without ANN
5.3 Induction Motor output without ANN
The above waveforms can be represents induction motor stator current, rotor current, load voltage, speed, torque.
6. Conclusion
This paper presented an Three phase Multilevel cascade Hbridge Inverter, which uses single DC source and PV system
as DC source and connected to three phase induction motor
is used as load to observe the performance characteristics of
the motor. The proposed Multilevel Inverter fed Induction
Motor can reduce switching losses and circuit complexity.
The method can be easily extended to an m-level inverter.
The cascaded inverter is subjected to other modulation
scheme. Simulations have been carried out in MATLAB–
Simulink to study the performance of the proposed
prototype.
References
[1] J. S. Lai and F. Z. Peng, “Multilevel converters – A new
breed of power converters,” IEEE Trans. Ind. Applicat.,
vol. 32, pp. 1098–1107, May/June 1996.
[2] J. Rodriguez, J.-S. Lai, and F. Z. Peng, "Multilevel
inverters: a survey of topologies, controls, and
applications," IEEE Trans. Ind. Electron., vol. 49, pp.
724-738, 2002.
[3] L. M. Tolbert, F. Z. Peng, and T. G. Habetler, "Multilevel
converters for large electric drives," IEEE Trans. Ind.
Applicat., vol. 35, pp. 36-44, 1999.
[4] H. Stemmler. Power electronics in electric traction
applications. IEEE conference of Industrial Electronics,
Control and Instrumentation, IECON’93, 2:7 07 – 713,
1993.
[5] H. Fujita, S. Tominaga, and H. Akagi. Analysis and
design of an advanced static VAR compensator using
quad-series voltage-source inverters. IEEE Industry Apps
Meeting,
[6] J. Rodriguez, S. Bernet, B. Wu, J. O. Pontt, and S.
Kouro, “Multilevel Voltage-source-converter Topologies
for
Industrial
Medium-voltage
Drives,”
IEEE
Paper ID: 03111405
Transactions on Industrial Electronics., vol. 54, no. 6, pp.
2930–2945, Dec. 2007
[7] K. Sivakumar, Anandarup Das, Rijil Ramchand, Chintan
Patel, and K. Gopakumar, “A Five-Level Inverter
Scheme for a Four-Pole Induction Motor Drive by
Feeding the Identical
Author Profile
G. Sathish Goud, has Received his B.Tech degree in
Electrical and Electronics Engineering from JNTUH,
Hyderabad, India and PG scholar in Dept of EEE,
AITH, JNTUH, Hyderabad, India. His is doing
currently research in Fuzzy logic controllers, ANN and electrical
power systems.
Kalimela Venkateswarlu has 5 years of teaching
experience in various engineering colleges. Presently
he is working as an Assistant Professor in
Annamacharya Institute of Technology and Sciences,
Hyd. He Received his B.Tech degree in Electrical and Electronics
Engineering from Aurora Engineering college,bhongir, Hyderabad,
India and Masters of engineering (M.E) in college of Engineering ,
Osmania University Hyderabad, India. His Research interests are
including artificial intelligence techniques, power electronic
&drive, fact devices.
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